Buggy code:
public class MapEntriesPropertyController extends PropertyController < Map < String , Object > , Object > { private final Map < String , PropertyDescription > attributesMap ; public static LabelProvider CLICK_TO_ADD = new LabelProvider ( ) { @ Override public String getText ( Object element ) { } } ; public MapEntriesPropertyController ( String id , String displayName , Map < String , PropertyDescription > map ) { } @ Override public CellEditor createPropertyEditor ( Composite parent ) { } @ Override protected IPropertyConverter < Map < String , Object > , Object > createConverter ( ) { } protected class MapPropertySource extends ComplexPropertySource < Map < String , Object > > { private static final String REMOVE_VALUE = "<removed>&*^&^%&$#@^%$&%%^#$*$($" ; public MapPropertySource ( ComplexProperty < Map < String , Object > > complexProperty ) { } @ Override public IPropertyDescriptor [ ] createPropertyDescriptors ( ) { } @ Override public Object getPropertyValue ( Object id ) { } @ Override protected Map < String , Object > setComplexPropertyValue ( Object id , Object v ) { } protected String toJSExpression ( Object v ) { } } protected abstract class AbstractAddEntryCellEditor extends CellEditor { private Map < String , Object > value ; protected Button button ; public AbstractAddEntryCellEditor ( Composite parent ) { } protected Pair < String , String > parseText ( String txt ) { } protected boolean allowNewKey ( String txt ) { } protected void addEntry ( String txt ) { } @ Override protected Control createControl ( Composite parent ) { Composite composite = new Composite ( parent , SWT . NONE ) ; addInput ( composite ) ; button = new Button ( composite , SWT . PUSH ) ; button . setImage ( PlatformUI . getWorkbench ( ) . getSharedImages ( ) . getImage ( IMG_OBJ_ADD ) ) ; addSelectionListener ( ) ; button . setEnabled ( false ) ; GroupLayout groupLayout = new GroupLayout ( composite ) ; SequentialGroup sequentialGroup = groupLayout . createSequentialGroup ( ) ; sequentialGroup . add ( getInput ( ) , PREFERRED_SIZE , 135 , Integer . MAX_VALUE ) ; sequentialGroup . addPreferredGap ( RELATED ) . add ( button ) ; groupLayout . setHorizontalGroup ( sequentialGroup ) ; ParallelGroup parallelGroup = groupLayout . createParallelGroup ( CENTER , false ) ; <START_BUG> parallelGroup . add ( button , DEFAULT_SIZE , DEFAULT_SIZE , Integer . MAX_VALUE ) ; <END_BUG> parallelGroup . add ( getInput ( ) , PREFERRED_SIZE , DEFAULT_SIZE , PREFERRED_SIZE ) ; groupLayout . setVerticalGroup ( parallelGroup ) ; composite . setLayout ( groupLayout ) ; return composite ; } protected void addSelectionListener ( ) { } @ Override protected Map < String , Object > doGetValue ( ) { } @ Override protected void doSetValue ( Object val ) { } @ Override protected void doSetFocus ( ) { } protected abstract Control getInput ( ) { } protected abstract void addInput ( Composite composite ) { } protected abstract void setInputText ( String string ) { } protected abstract String getInputText ( ) { } } protected class AddEntryCellEditor extends MapEntriesPropertyController . AbstractAddEntryCellEditor { private Text text ; public AddEntryCellEditor ( Composite parent ) { } @ Override protected void setInputText ( String string ) { } @ Override protected Control getInput ( ) { } @ Override protected String getInputText ( ) { } @ Override protected void addInput ( Composite composite ) { } } protected class AddEntryComboCellEditor extends MapEntriesPropertyController . AbstractAddEntryCellEditor { private Combo combo ; public AddEntryComboCellEditor ( Composite parent ) { } @ Override protected Control getInput ( ) { } @ Override protected String getInputText ( ) { } @ Override protected void setInputText ( String string ) { } @ Override protected void addInput ( Composite composite ) { } } }

Fix:
parallelGroup . add ( button , 0 , 0 , Integer . MAX_VALUE ) ;